The expansion of mechanisms of direct democracy in Latin America took place in a context of a serious crisis of political legitimacy which was especially acute during the last decades of the 20th and the first one of the 21st century. In Argentina mechanisms of direct democracy on the national level were introduced during the constitutional reforms of 1994 - although in a very limited way, addressing parliament. On the sub-national level where the provinces and municipalities have more leeway the picture looks somewhat different. In the present working paper we identify the main characteristics of Argentina's instruments of direct democracy on the sub-national level (provinces and municipalities), analyse their main institutional designs and make a beginning for an exploratory analysis on how these mechanisms are put into practice in the provinces. The analysis makes use of data elaborated from all provincial constitutions and 135 municipal charters.